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We investigated differences in the hydrogen thermal desorption mechanism for Ni-Ti superelastic alloys following hydrogen charging by cathodic charging in a 0.9% NaCl aqueous solution and by immersion testing in a 0.2% APF aqueous solution. For the immersed specimen, the presence of corrosion products on the surface resulted in an upward shift of the hydrogen desorption peak by approximately 100 °C. When the total amount of desorbed hydrogen was almost the same for both specimens, a higher fraction was desorbed at temperatures below 200 °C for the cathodically charged specimen. Furthermore, a larger amount of hydride was formed for the cathodically charged specimen. These results indicate that the hydrogen thermal desorption mechanism depends on the presence of corrosion products on the surface and the amount of hydride formed.

A plastic balloon of 5000 m^3 was launched at Syowa Station (L=61), Antarctica, at 1138 UT on December 12, 1976, and the horizontal electric field and auroral X-rays (>25 keV) were simultaneously measured for about 10 hours m the stratosphere. During the balloon flight a weak geomagnetic substorm occurred corresponding to the eastward electrojet in the afternoon side of the auroral zone, and the electric field increased from 10 mV/m to 40 mV/m. There were good correspondences between the southward electric field and geomagnetic horizontal component and between the westward electric field and declination. Observed auroral X-rays were homogeneous throughout the all sky and of diffuse type. The X-rays were enhanced three times during the substorm. The electric field clearly decreased on the second X-rays event but there was no clear change on the other two events. There was no special change in the electric field direction during the geomagnetic substorm. One hour averages of the observed electric field show a clear S_q^p pattern. The height-integrated conductivities were calculated from the observed electric field and the geomagnetic variations at Syowa Station, getting the values of 1-10 mho. The Hall conductivity increased during the substorm.

Quiet-time DC and AC (18-220 Hz) electric fields were observed in the lower ionosphere up to 118 km by means of spherical double probes on board the sounding rocket S-210JA-29 which was launched from Syowa Station at 16.15 UT on July 12, 1977 The DC electric field intensity was～10 mV/m in the lower E region where the electron density was 2-3×10^4 cm^, while it increased sharply up to ～130 mV/m above the altitude of ～110 km with a good correlation with the decrease in the electron density. 0nly weak AC noise was observed in the whole altitude range

The measurements of vector electric fields and currents were made with two plastic balloons of 5,000 m^3 launched from Syowa Station (L=8.4), Antarctica, on 28 November and 29 December, 1972. The results give the following. (1) The vertical electric field and current at the altitude of 30km are 0.12-0.21 V/m and 1.3-2.2 x10^ A/m^2 respectively, and their diurnal variations are roughly consistent with the expected variation from the average world-wide thunderstorm activity. (2) The electrical conductivities were estimated from the ratio of the electric current to the electric field giving the average value of 1 x 10^ mho/m at the altitude of 30 km. This value is about twice as large as that in Japan. This can be explained by the latitudinal effect of the cosmic ray ionization in the atmosphere. (3) Enhancements of the electric field and current were observed in both vertical and horizontal components of the magnitude of about 80 mV/m and 0.8 x 10^ A/m^2 respectively at an initial stage of a magnetic substorm. The vertical electric field on the ground was also correspondingly enhanced by about 80 V/m at the same time. (4) Comparisons of observed horizontal electric field vectors with the magnetic fields observed at Syowa Station show that the magnetic field variations are caused by the ionospheric Hall current. (5) One hour averages of the horizontal electric field show large scale convection fields consistent with S^p_q in the polar ionosphere and with DP-2 in the equatorial magnetosphere. The average ionospheric and magnetospheric equatorial electric fields were 40 mV/m and 0.98 mV/m respectively, and corresponding plasma convection velocities were estimated to be 700 m/s and 22 km/s respectively.

DC and AC (8-110 Hz) electric fields were observed in the auroral ionosphere up to 120 km with spherical double probes on board the sounding rockets S-210JA-24 and 25 at Syowa Station. The rockets passed close to auroras. The DC electric fields observed during substorms at magnetic midnight are composed of the height-independent electric field of about 20 mV/m and the local electric field of up to 30 mV/m. The former electric field is the large scale electric field generally existing in the auroral ionosphere, and the latter local electric field will be the effect of space charges produced by precipitating auroral particles, peaking at the heights between 100-115 km. Strong AC noises were observed in the limited altitude range of 96-112 km during both the ascent and the descent. The noise frequencies varied with altitude and were ranged between 20 and higher than 110 Hz. The noises appeared in the direction perpendicular to the DC electric field. These characteristics suggest that the noises might be generated by plasma instability in the ionospheric current layer.